CN113462382B

CN113462382B - Rare earth color light conversion material, color converter containing same and light-emitting device

Info

Publication number: CN113462382B
Application number: CN202110736364.6A
Authority: CN
Inventors: 史华红; 宋森川; 李岱远; 梁东
Original assignee: Foshan Huaeuropium Photoelectric Material Co ltd
Current assignee: Foshan Huaeuropium Photoelectric Material Co ltd
Priority date: 2021-06-30
Filing date: 2021-06-30
Publication date: 2023-12-05
Anticipated expiration: 2041-06-30
Also published as: CN113462382A

Abstract

The invention discloses a rare earth color light conversion material, which is prepared by compounding a red luminescent organic rare earth material and a green luminescent organic rare earth material. The invention solves the two technical problems of health hazard of high-energy blue light and discontinuous spectrum deletion of the common white light LED light source, improves the overall photophysical performance of the common white light LED lighting device, and shows the excellent characteristics of high color rendering index and low blue light hazard of healthy lighting.

Description

Rare earth color light conversion material, color converter containing same and light-emitting device

Technical Field

The invention relates to the technical field of illumination, in particular to a rare earth color light conversion material, a color converter containing the color light conversion material and a light-emitting device.

Background

LEDs (light emitting diodes) are called fourth generation illumination light sources, which are spontaneous emission semiconductor devices that convert electric energy into light energy, and their light emitting devices gradually replace conventional light sources such as incandescent lamps and fluorescent lamps. It has higher conversion efficiency, 80% energy savings, smaller volume and longer life than incandescent lamps, and lower power than conventional light sources. LEDs are used in a variety of lighting applications such as indoor lighting, traffic signals, automotive lighting, or display backlighting systems.

The light emission of the LED is based on the recombination of holes injected into an N region from a P region and electrons injected into a P region from the N region in a micron-sized region near the PN junction in the PN junction of the semiconductor, and the electrons in the N region and the holes in the P region respectively, so that spontaneous-radiated fluorescence is generated. The LED produces light in a narrow spectral wavelength range with its central emission peak wavelength determined by the encapsulated luminescent material (also known as "fluorescent material" or "radiation conversion luminophore" or "phosphor" or "fluorescent colorant" or "fluorescent dye"). For example, blue to green LEDs may be produced using nitride semiconductors such as InN (indium nitride), inGaN (indium gallium nitride), alN (aluminum nitride), or GaN (gallium nitride); the red LEDs may be produced using semiconductors such as GaP (gallium phosphide), gaAsP (gallium arsenide phosphide) or AlGaAs (aluminum gallium arsenide).

White light emitting LEDs are used as light sources in various applications or as backlights in full color displays (including in flat panel display applications) due to their long lifetime, high reliability and low power consumption. Two methods are commonly used for LEDs to produce white light, the basis for which is the superposition (mixing) of the various colors.

In the prior art, the emitted light of the white light LED generally cannot uniformly cover the visible spectrum range, the emission spectrum of the natural light or incandescent light source cannot be simulated, the color rendering index is low, and the white light LED has the problems of blue light hazard and 'blue-rich' photo-biological safety, and is mainly expressed in the aspects of near ultraviolet radiation damage of eyes, photochemical damage of retina blue light and the like.

In recent years, a new generation of white light LED health illumination products having higher biosafety and color development characteristics than conventional white light LEDs has become the mainstream of market development. The full spectrum white light LED meets IEC 62471 light radiation safety standard, blue light radiation reaches photo-biological safety non-dangerous level (Exempt Group-RG 0), spectrum coverage is wide (380-780 nm), spectrum is close to solar visible light spectrum, spectrum continuity is good, spectrum distribution has no obvious wave crest and wave trough, color rendering index is excellent, and color reduction capability to objects is strong.

Obtaining LED health lighting products, the prior art still starts with traditional inorganic rare earth luminescent materials to realize the color coordinates of white light LEDs at the LED chip packaging level close to (0.33 ): changing the type and quantity of the doped rare earth luminescent material under the condition that the light efficiency of the YAG luminescent material is not affected so as to lead the emission spectrum to move to the long wave direction; and secondly, a red or orange-red luminescent material is properly added to make up for the deficiency of the spectral red light component. The method can improve the color rendering index of the white light LED but can not solve the problem of damage caused by high-energy blue light radiation, is limited by the problems of low luminous efficiency, poor stability and the like commonly existing in the prior rare earth materials, is not suitable for the prior production line equipment, has complicated process and huge investment, and is used for developing the high-efficiency luminous material excited by blue light or purple light to be the starting point and the end point of the prior LED healthy lighting technology.

Organic luminescent materials, despite their superior photophysical properties, have limited their use in LED lighting devices (applied directly and without intervening gaps to LED dies, e.g., in drop or hemispherical packages on LED chips or off-chip coatings), suffer from high thermal and radiation stresses over their lifetime of the light source, and undergo degradation and failure of their lighting properties. Degradation may be due to low photostability, low thermal stability, and/or high sensitivity to moisture and oxygen of the material. For these reasons, basf proposes the concept of "remote phosphor", making the organic luminescent material together with the plastic substrate into a color converter (also called "converter" or "light converter", which generally comprises a polymer layer and one or more radiation converting luminophores) spatially separate from the LED light source. In this way, the extent of the influence of the generated heat and radiation of the light source on the organic fluorescent material is greatly reduced. Furthermore, LEDs according to the "remote phosphor" concept are more energy efficient than LEDs according to the "phosphor on chip" concept. This is also known as hybrid LED technology, using either cool white LEDs or blue LEDs as excitation light sources, exciting a color converter made of organic luminescent material and plastic, to achieve the desired spectral range, color temperature and color rendering index.

The prior application to basf (publication No. CN109803969 a) relates to perylene bisimide compounds and their use in color converters. Such materials were reported in 1989 to have excellent weatherability and high fluorescence quantum efficiency. The invention provides a novel organic fluorescent material, which has the following application properties: is suitable for down-converting a cool white LED having a correlated color temperature of 6000-20000K into white light having a lower correlated color temperature; the LED light source is suitable for downwards converting blue LED light into white light; high light stability; high thermal stability; high chemical stability to moisture and oxygen; high fluorescence quantum yield in the polymer matrix; high compatibility with LED manufacturing operations; good chemical resistance, especially resistance to bleaching with hypochlorite and solvent resistance (such as toluene, acetone or methylene chloride); good boiling water resistance; high compatibility with a variety of formulations, especially for photo/thermal curing thermoplastic polymer formulations.

Although the design of basf can meet the requirement of full spectrum illumination, as the perylene bisimide compound belongs to an organic fluorescent material, the half-width is between 80 and 100nm, the STOKES displacement is less than 50nm, the color purity of light is low, and the emission peak and the absorption peak between different materials are seriously overlapped, so that the light efficiency is reduced.

Rare earth luminescent materials have narrow-band emission characteristics that play a monopolizing role in the history of display and illumination. For example: in cathode ray tube, Y ₂ O ₂ S Tb is used as green powder, Y ₂ O ₃ :Eu/Y ₂ O ₂ Eu is used as red powder; in energy-saving fluorescent lamp Tb ³⁺ :LaPO ₄ ,Ce ³⁺ :LaPO ₄ And Eu ³⁺ :Y ₂ O ₃ Respectively used as green powder, blue powder and red powder; in the ancient cooking vessel, the annual yield of these powders reaches thousands of tons. Because of the rapid development of LED technology, the demand for these fluorescent materials has greatly shrunken. In a white LED, yellow-green powder YAG (Y ₃ Al ₅ O ₁₂ Ce) and 465nm blue light chip to emit white light. Europium-containing red powder (Sr [ Li ] ₂ Al ₂ O ₂ N ₂ ]:Eu ²⁺ ) Providing a good way to improve color temperature and color rendering index. Although these fluorescent materials are stable to heat, they are not easily decomposed. However, the heat generated by the chip can lead to the rapid luminescence of the fluorescent material due to the direct contact of the fluorescent material and the chipAnd decreases, thereby limiting the application of this technique. Considering that inorganic rare earth luminescent materials are not easy to be uniformly mixed with plastics, attention is mainly focused on organic rare earth complexes, namely rare earth ions are combined with organic ligands to form an organic rare earth complex luminescent material. Through molecular design and regulation synthesis, the organic rare earth complex luminescent material which is easy to be uniformly mixed with plastics can be obtained. Thus, the rare earth color converter according to the present invention can be obtained. The rare earth color converter is combined with a purple light/blue light LED or a white light LED, and the spectrum is reduced in blue, increased in green and increased in red, so that the LED lamp for healthy illumination or the backlight plate light source system for ultra-high definition display is produced on the premise of not changing the existing materials and production process. Successful development and industrialization of the LED rare earth color converter provides a great opportunity for the review of rare earth luminescent materials in the fields of display and illumination.

The unique optical properties of rare earth materials are determined by their valence shell electron arrangement. The 4f sub-layer of rare earth ions fills the electrons and 4f splits under the combined influence of homolayer electron repulsion and spin-orbit coupling. The rare earth ions exist as single 4f electrons and f-f electron transitions within the 4f sub-layer. The 4f sub-layer is positioned in the inner layer of the ion and is shielded by the 5d sub-layer and the 6s sub-layer, and f-f transition is slightly influenced by the surrounding environment and presents a sharp linear band. And the excited state has a relatively long lifetime, which is an advantage of its luminescence. However, rare earth ions have a small absorption coefficient in the near ultraviolet region, and thus have low luminous efficiency. When they form complexes with some organic ligands such as β -diketones, their luminous efficiency is greatly enhanced. Such complexes are commonly referred to as organic rare earth complex luminescent materials. The organic portion of these complexes absorbs light, through intermolecular energy transfer, emitting characteristic luminescence of rare earth ions. This phenomenon is also called "antenna effect".

Their emission spectra have the following characteristics: (1) The entire visible light region is covered, such as blue light emission from cerium (III), orange light emission from samarium (III), red light emission from europium (III), green light emission from terbium (III), yellow light emission from dysprosium (III), blue light emission from thulium (III) and europium (II). In addition, neodymium (III) and erbium (III) can emit infrared and near infrared light. (2) Their luminescence is caused by 4f inner layer electron mobility, and therefore their spectra are determined by the central metal ion and do not change with ligand changes; (3) The emission spectrum of organic molecules is generally broad, with a half-width of about 80-100 nm. The rare earth complex emits in a narrow band with a spectral half-peak width smaller than 10nm, and has the advantage of pure chromaticity; (4) Their photoluminescence efficiency is high, for example, the reported photon efficiency of solid europium complexes reaches 85%.

Bipyridine triazole rare earth complexes are described in the patent technology of Chinese patent publication No. CN 103044466B; o-phenanthroline triazole rare earth complex is described in the patent technology with publication number CN 103172649B; the tetrazole rare earth complex substituted by nitrogen-containing bidentate heterocycle is described in the patent technology of Chinese patent publication No. CN 103242354B; the technology of Chinese patent publication No. CN103265567B describes 1,2, 3-triazole rare earth complexes substituted by nitrogen-containing bidentate heterocycles; quinoline triazole rare earth complexes are described in the patent publication No. CN 108191827A. The complexes are all prepared into novel organic rare earth complex luminescent materials by a coordination mode of combining a uniform ligand with a rare earth center ion. The novel rare earth complex is characterized in that triazole or tetrazole groups in the ligand are taken as anion donors, and are combined with central rare earth metal cations to realize complex electroneutrality, so that the connecting bond energy of the ligand and the central metal ions is not only a coordination bond, but also positive and negative charge interaction force between the ligand and the central metal ions exists, and the stability of the complex is improved as a whole. The organic rare earth complex has high light and heat stability, and is suitable for vapor deposition film forming process, solution film forming process and physical blending process to prepare devices. The preparation method has high yield, good product purity, short reaction time, simple operation and low comprehensive production cost.

Therefore, the organic rare earth complex luminescent material with high saturation chromaticity, low toxicity, high stability to light and heat and high chemical stability to moisture and oxygen is applied to the device design development of the white light LED healthy lighting device, and particularly the non-LED chip direct contact photoluminescence (light conversion) device is developed, so that the luminescent material is an innovative means for realizing the white light LED healthy lighting.

Disclosure of Invention

In order to solve the problems in the prior art, the invention provides a rare earth color light conversion material, a color converter and a light-emitting device containing the color light conversion material, and the light conversion function of the rare earth color light conversion material is used for supplementing blue-green light and red-orange light with relatively low (relatively missing) spectrum of a common white light LED after converting high-energy blue light, so that the problem of vision hazard caused by the high-energy blue light is solved, and the problem of color development of discontinuous spectrum is solved at the same time, thereby realizing the performance upgrading of the common white light LED with lower cost and simpler and more convenient process and meeting the basic index requirements of healthy illumination. The color converter (also called as a light conversion component or a light conversion device or a color conversion device) developed by using the rare earth color light conversion material and a light emitting device applying the color converter are separated from a common white light LED light source in physical space, are not directly influenced by the thermal stress and the radiation stress of an LED chip, and can meet different development requirements of the LED healthy lighting field on lamp design or reconstruction.

In order to achieve the above purpose, the invention adopts the following technical scheme:

the rare earth color light conversion material is prepared by compounding a red luminescent organic rare earth material and a green luminescent organic rare earth material; the red luminescent organic rare earth material is at least one of tris [5- (2, 2' -bipyridyl-6-yl) -1,2, 4-1H-triazole ] europium (III), tris [5- (1, 10-phenanthroline-2-yl) -1,2, 4-1H-triazole ] europium (III), tris [5- (4, 4' -dimethyl-2, 2' -bipyridyl-6-yl-1, 2, 4-1H-triazole ] europium (III), tris [ 3-fluoromethyl-5- (2, 2' -bipyridyl-6-yl) -1,2, 4-1H-triazole ] europium (III), tris [5- (2, 2' -bipyridyl-6-yl) -1,2,3, 4-1H-tetrazole ] europium (III) and tris [5- (1, 10-phenanthroline-2-yl) -1,2,3, 4-H-tetrazole ] europium (III), and the green luminescent organic rare earth material is the material of tris [ 3-fluoromethyl-5- (2, 2' -bipyridyl-6-yl) -1,2, 4-1H-triazole ] europium (III), tris [5- (2, 2' -bipyridyl-6-yl) -1,2,3, 4-H-tetrazole ] europium (III), and tris [5- (1, 10-phenanthroline-2-yl) -1, 3, 4-H-tetrazole ] europium (III), at least one of tris [5- (1, 10-phenanthroline-2-yl) -1,2,3, 4-1H-tetrazole ] terbium (III), tris [ 3-bromo-5- (2, 2' -bipyridin-6-yl) -1,2, 4-1H-triazole ] terbium (III), tris [5- (2, 2' -bipyridin-6-yl) -1,2,3, 4-1H-tetrazole ] terbium (III), tris [ 3-fluoromethyl-5- (2, 2' -bipyridin-6-yl) -1,2, 4-1H-triazole ] terbium (III); the rare earth color light conversion material is combined with a polymer matrix, and the addition amount of the rare earth color light conversion material in the polymer matrix depends on the correlated color temperature to be achieved.

Preferably, the red luminescent organic rare earth material and the green luminescent organic rare earth material are proportioned according to the following weight proportion ranges to obtain a yellow luminescent organic rare earth material, wherein the proportion range is 1:1-10.

Preferably, the red luminescent organic rare earth material and the green luminescent organic rare earth material are proportioned according to the following weight proportion ranges to obtain the red orange luminescent organic rare earth material, wherein the proportion range is 1:0.1-1.

Preferably, the red luminescent organic rare earth material and the green luminescent organic rare earth material are mixed according to the following weight proportion to obtain an orange luminescent organic rare earth material, wherein the proportion range is 1:0.1-4.

Preferably, the red luminescent organic rare earth material and the green luminescent organic rare earth material are proportioned according to the following weight proportion in the range of 1:0.01-1.

According to the spectrum difference of the LED lamps with different color temperatures, the types and the proportions of rare earth color light conversion materials for realizing the color conversion are different, the key for realizing the light conversion effect of higher color rendering index and lower blue light component spectrum ratio is that the proportion among the different rare earth color light conversion materials is accurately regulated, the aim of regulating and improving the spectrum of the LED lamps is realized for better use together with red luminescent organic rare earth materials, and the developed orange luminescent organic rare earth materials, yellow green luminescent organic rare earth materials, red orange luminescent organic rare earth materials and yellow green luminescent organic rare earth materials are key components for realizing regulation and improvement of the spectrum of the LED lamps. The rare earth color light conversion material of the present invention has high light stability when irradiated with light generated by a blue LED having a center emission wavelength of 380 to 480nm, particularly when irradiated with ultraviolet light.

The invention also provides another technical scheme, a color converter comprises the rare earth color light conversion material and a polymer matrix material, wherein the rare earth color light conversion material is combined with the surface of the polymer matrix material or combined in a blending way. In this embodiment, the thickness of the polymer matrix containing the rare earth color conversion material is 25 μm to 600 μm.

For the purposes of the present invention, color converter is understood to mean a device capable of absorbing light of a particular wavelength and converting it into light of other wavelengths.

Preferably, the polymer matrix material is selected from the group consisting of Low Density Polyethylene (LDPE), polypropylene (PP), polystyrene (PS), polycarbonate (PC), polymethyl methacrylate (PMMA), polyvinylpyrrolidone (PVP), polyvinyl acetate (PVAc), polybutylene (PB), silicone, polyacrylate, epoxy resin, polyvinyl alcohol (PVA), poly (ethylene-vinyl alcohol) copolymer (EVA, EVOH), polyacrylonitrile, polyvinylidene chloride (PVDC), polystyrene acrylonitrile (SAN), polybutylene terephthalate (PBT), polyethylene terephthalate (PET), polyvinyl butyrate (PVB), polyvinyl chloride (PVC), polyamide, polyoxymethylene (POM), polyimide (PI), polyetherimide (PEI) and mixtures thereof.

Preferably, the color converter comprises at least one inorganic white pigment as a diffuser. Suitable scatterers are inorganic white pigments, such as titanium dioxide, lithopone, zinc sulfide, barium sulfate, calcium carbonate, zinc oxide, etc., which have an average particle size according to DIN 13320 of from 0.01 μm to 10. Mu.m, preferably from 0.1 μm to 1. Mu.m, further preferably from 0.15 μm to 0.5. Mu.m, in particular titanium dioxide being employed as the scatterer. The content of the scatterers is generally 0.01% by weight to 2.0% by weight, preferably 0.05% by weight to 1% by weight, more preferably 0.1% by weight to 0.5% by weight, based in each case on the polymer comprising the scatterer layer.

Preferably, the flame retardant coating also comprises an auxiliary agent, wherein the auxiliary agent is at least one of a flame retardant, an antioxidant, a light stabilizer, an ultraviolet absorber, a blue light absorber, a free radical scavenger and an antistatic agent.

The amount of rare earth color conversion material added to the polymer matrix material depends on the correlated color temperature to be achieved. For example, the light emitted from the LED may be tuned to a longer wavelength to obtain white light with a desired color temperature by increasing the concentration of the yellow light converting material and the red light converting material. The concentration of the rare earth color conversion material in the polymer matrix material is set according to the thickness of the color converter and the type of polymer. If a thin polymer layer is used, the concentration of rare earth color conversion materials is typically higher than if a thick polymer layer is used. The particular concentration of rare earth color conversion material required to convert a particular wavelength depends on the type of LED that is to produce light. Conversion of light produced by blue LEDs typically requires a higher concentration of rare earth color conversion material addition in order to achieve the same color temperature of white light as compared to white LEDs.

The concentration of the red-emitting organic rare earth material of the present invention is usually 0.0001 to 5% by weight, preferably 0.001 to 1% by weight, and more preferably 0.002 to 0.5% by weight, based on the amount of the polymer. If used in combination, the concentration of the other yellow-emitting organic rare earth material or the yellow-green-emitting organic rare earth material is generally from 0.002 to 5% by weight, preferably from 0.003 to 0.4% by weight, based on the amount of the polymer. The ratio of the other yellow-emitting organic rare earth material or the yellow-green-emitting organic rare earth material to the at least one red-emitting organic rare earth material is typically in the range of 1:1 to 1:20, preferably 1:2 to 1:10, further preferably 1:2 to 1:5, for example 1:2.1 or 1:3 or 1:4.

The addition ratio of the rare earth color light conversion material depends on the selected basic light source. For a desired set color temperature, the ratio of yellow luminescent organic rare earth material to red luminescent organic rare earth material is significantly greater when light is emitted by a blue LED having a center emission wavelength of 380-480nm than when light is emitted by a white LED having a color temperature of 6000-20000K.

The color converter can be manufactured by different production processes, and according to the different combination modes of the rare earth color light conversion material and the polymer matrix material, the rare earth color light conversion material is combined with the polymer matrix material by adopting at least one preparation process of casting molding, granulating and tabletting molding, granulating and film blowing molding, coating and film scraping molding and printing molding, and the preferable combination curing modes are natural curing, heating curing, light curing and photo-thermal combination curing. The preparation process can be an independent manufacturing flow of one-time processing and forming, and can also be a step-by-step manufacturing flow of multiple processing and forming. Specific examples are, in a coating film-forming preparation process, a manufacturing process of the color converter comprising dissolving at least one polymer matrix material, rare earth color conversion material and other auxiliary materials in a solvent, followed by coating film-scraping to remove the solvent; in the preparation process of granulating, film blowing and forming, the manufacturing process of the color converter comprises extruding rare earth color light conversion materials, other auxiliary materials and at least one polymer matrix, and granulating, film blowing after cooling.

In order to improve the high chemical stability against water and oxygen, the color converter further comprises at least one barrier layer against oxygen and/or water, which is any one of glass, quartz, metal oxide, silicon dioxide, a multilayer system consisting of alternating layers of silicon dioxide and aluminum oxide, titanium nitride, silicon dioxide/metal oxide multilayer material, polyvinyl alcohol, polyacrylonitrile, polyvinylidene chloride (PVDC), liquid Crystal Polymer (LCP), polystyrene-acrylonitrile (SAN), polybutylene naphthalate (PBN), polybutylene terephthalate (PBT), polyethylene naphthalate (PEN), polyethylene terephthalate (PET), polyvinyl chloride (PVC), polyvinyl Butyrate (PBT), polyamide, epoxy, polyoxymethylene, polyetherimide, polyimide, polymer derived from Ethylene Vinyl Acetate (EVA) and polymer derived from ethylene vinyl alcohol (EVOH).

The color converters of the present invention may optionally comprise other components, such as a backing layer. The backing layer may impart certain mechanical stability properties to the color converter. Common backing layer materials are glass or transparent rigid organic polymers such as polystyrene, polycarbonate, polymethacrylate or polymethyl methacrylate. The backing layer thickness is generally from 1mm to 10mm, preferably from 0.1mm to 5mm, and more preferably from 0.3mm to 2mm.

The color converter of the present invention may be manufactured in any desired geometry depending on the light emitting device, may be used in combination with LEDs in virtually any geometry, may have essentially any geometry, and is independent of the configuration of the light emitting device, preferably the color converter is a film, a plate, a sheet, a droplet pattern, a hemispherical pattern, a cylindrical, spherical surface lens or a cover plate.

Regardless of the three-dimensional shape, the color converter of the present invention may be constructed of a single layer or a multi-layer structure. When the color converter of the present invention comprises more than one rare earth color conversion material, the rare earth color conversion materials and/or diffusers therein may be present in the same/different layers. When the color converter of the present invention comprises a plurality of rare earth color conversion materials, the rare earth color conversion materials may be present in the same layer adjacent to each other. When the color converter has a layered structure, then the layers are continuous and do not have any holes or spaces.

The invention also provides another technical scheme, namely a light-emitting device which comprises at least one LED and at least one color converter, wherein a gap is reserved between the LED and the color converter. The color converter is separated from a common white light LED light source in physical space, is not directly influenced by thermal stress and radiation stress of an LED chip, and can meet different development requirements of the LED healthy lighting field on lamp design or reconstruction.

The color converter of the invention is applied to a light emitting device in a remote photoluminescence setting. On the premise, the color converter is physically separated from the LED light source in space. In general, the distance between the LED light source and the color converter is 0.05cm-45cm, preferably 0.2cm-9.5cm, more preferably 0.4cm-2.9cm. The color converter and the LED may be in different media, such as dry air, rare gas, inert gas or other gases or mixtures thereof.

Preferably, the color converters may be arranged concentrically around the LEDs, and the specific application is not limited by the commercial specifications of the lighting product, including, but not limited to, LED spot lights, LED bulb lights, LED fluorescent lights, LED down lights, LED ceiling lights, LED panel lights, LED street lights, LED tunnel lights, LED landscape lights, LED plant lights, LED trunk lights, and the like. Belongs to the upgrading and optimizing technology of the existing white light LED illumination products and also belongs to the economic manufacturing technology of white light LEDs in the novel healthy illumination field.

Preferably, the light emitting device of the present invention comprises at least one LED having a central emission wavelength of 380nm to 480nm and at least one of the above-mentioned color converters, the color converter and the LED being physically separated in space. It is further preferred that the light emitting device comprises a plurality of LEDs selected from LEDs having a central emission wavelength of 380nm-480nm and LEDs having a color temperature of 6000-20000K, the color converter and the blue/white LEDs being arranged in a non-contact manner with a certain physical space gap.

In particular, the color converter is adapted to convert light generated by cold white light LEDs having a color temperature of 20000-6000K, e.g. 20000-8000K, 15000-7000K or 12000-8200K, to generate white light having a lower color temperature, e.g. 2000-5000K or 2500-4000K. That is, the color converter of the present invention can shift (red shift) the emission wavelength of the white light source in a longer wavelength direction, thereby generating white light with warm light color tone, and improving the color rendering index of the light emitting device. Similarly, light generated by an LED having a center emission wavelength of 380-480nm can be converted to light of a second, longer wavelength by passing the light from such LED through a color converter comprising a light converting material. In the process, the color converter also simultaneously realizes the function of absorbing and converting the high-energy surplus blue light of the LED light source, reduces the spectrum duty ratio of the high-energy blue light and protects the vision health.

The invention has the beneficial effects that: the light conversion function of the rare earth color light conversion material is used for supplementing blue-green light and red-orange light with relatively low (relatively missing) spectrum of the common white light LED after converting high-energy blue light, so that the problem of vision damage caused by high-energy blue light is solved, and the problem of color development of discontinuous spectrum is solved, thereby realizing the performance upgrading of the common white light LED with lower cost and simpler and more convenient process and meeting the basic index requirement of healthy illumination.

On the other hand, the color converter can be manufactured by different production processes, and the rare earth color light conversion material is combined with the polymer matrix material by at least one preparation process of casting molding, granulating and tabletting molding, granulating and film blowing molding, coating and film scraping molding and printing molding according to the different combination modes of the light conversion material and the polymer matrix material. The color converter can be manufactured in any desired geometry depending on the light emitting device, can be used in combination with LEDs in virtually any geometry, can have essentially any geometry, and is independent of the construction of the light emitting device, and is product-adaptable.

In the present invention, the term "color converter" is also referred to as "light conversion device" or "light conversion assembly" or "light conversion device" or "color conversion device". These terms are used interchangeably and are understood to mean all physical devices capable of absorbing light of a particular wavelength and converting it to light of a second wavelength. The color converter is part of a light emitting device, especially a light emitting device using an LED or an OLED as a light source, so that blue light may be partially converted into visible light having a longer excitation wavelength.

LEDs with a central emission wavelength of 380-480nm and LEDs with a color temperature of 6000-20000K are both mature commercial products. The prior various LED light sources are commercial mass-production LED light sources.

In the present invention, a "white light LED" means an LED capable of emitting light in the blue range of the electromagnetic spectrum, the peak of which is between 380 and 480nm, preferably 440 and 470nm, and more preferably 440 and 460nm. Standard indium gallium nitride (InGaN) based white LEDs are fabricated on sapphire substrates and the dominant peak emission wavelength is typically around 450 nm.

Drawings

Fig. 1 is a schematic structural diagram of an LED bulb lamp device in embodiment 1 of the present invention;

FIG. 2 is a schematic diagram of a T8/T5 type LED fluorescent lamp device in embodiment 2 of the present invention;

fig. 3 is a schematic structural diagram of an LED row lamp device in embodiment 3 of the present invention;

fig. 4 is a schematic structural diagram of an LED down lamp device in embodiment 4 of the present invention;

fig. 5 is a schematic structural diagram of an LED panel light device in embodiment 5 of the present invention.

Reference numerals illustrate:

LED lamp bead 101, LED bulb lamp shade 102, radiator 103, driving power supply 104, LED bulb lamp cap 105, T8/T5 type LED fluorescent lamp substrate 201, T8/T5 type LED fluorescent lamp shade 202, T8/T5 type LED fluorescent lamp cap 203,

An LED row lamp substrate 301, an LED row lamp mask 302, a series connection joint 303,

LED down lamp housing 401, lamp bead belt 402, LED down lamp light guide plate 403, light-converting polymer plate 404, LED down lamp face mask 405,

The LED panel lamp comprises an outer cover 501, a light conversion material film 502, an LED panel lamp light guide plate 503, an LED panel lamp strip 504, a reflector 505, a protective layer 506 and a frame base 507.

Detailed Description

The technical solutions of the present invention will be clearly and completely described in conjunction with the embodiments of the present invention, and it is apparent that the described embodiments are only some embodiments of the present invention, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention. The equipment and reagents used in the present invention are conventional commercially available products in the art, unless specifically indicated.

The invention relates to an organic rare earth material, in particular to five organic rare earth materials in the published patent technology, wherein the first class is bipyridine triazole rare earth complex, the structural formula and the preparation method thereof refer to patent literature (patent name: bipyridine triazole rare earth complex and the preparation method thereof, publication number: CN 103044466B), and the bipyridine triazole rare earth complex is selected from formulas A1-A4:

The second type is phenanthroline triazole rare earth complex, the structural formula and the preparation method thereof refer to patent literature (patent name: phenanthroline triazole rare earth complex and preparation method thereof, publication number: CN 103172649B), and the phenanthroline triazole rare earth complex is selected from the formulas B1-B4:

the third class is a nitrogen-containing bidentate heterocycle-substituted tetrazole rare earth complex, the structural formula and the preparation method of which are described in patent literature (patent name: nitrogen-containing bidentate heterocycle-substituted tetrazole rare earth complex and preparation method thereof, publication number: CN 103242354B), and the nitrogen-containing bidentate heterocycle-substituted tetrazole rare earth complex is selected from the group consisting of formulas C1-C2:

the fourth class is a nitrogen-containing bidentate heterocycle-substituted 1,2, 3-triazole rare earth complex, the structural formula and the preparation method thereof refer to patent literature (specialty name: nitrogen-containing bidentate heterocycle-substituted 1,2, 3-triazole rare earth complex and its synthesis method, publication number: CN 103265567B), and the nitrogen-containing bidentate heterocycle-substituted 1,2, 3-triazole rare earth complex is selected from formulas D1-D2:

the fifth category is quinoline triazole rare earth complex, the structural formula and the preparation method thereof refer to patent literature (patent name: quinoline triazole rare earth complex, preparation method and application thereof, publication number: CN 108191827A), and the structural formula of the quinoline triazole rare earth complex is as follows:

The five types of organic rare earth materials described in the above patent documents have structural formulas, wherein R1, R2, R3, R4, and R5 represent organic substituents of each complex, and Ln represents a central rare earth ion of each complex. The selection range of the organic functional groups of the R1-R5 substituent groups and the selection range of Ln center rare earth ions are consistent with the selection range described in the patent documents.

Suitable rare earth color light converting materials based on photoluminescent premises may be green luminescent organic rare earth materials, yellow-green luminescent organic rare earth materials, yellow luminescent organic rare earth materials, orange luminescent organic rare earth materials, red-orange luminescent organic rare earth materials and red luminescent organic rare earth materials selected from the five classes of organic rare earth materials mentioned above, and may be any rare earth color light converting material capable of absorbing light having a wavelength in the range of 250-500nm and emitting light having a wavelength longer than the absorbed light, in particular emitting light having a wavelength in the wavelength range of more than 450nm, for example in the wavelength range of 450-600nm or 450-650 nm. Preferably, the combined use of rare earth color conversion materials can provide a color converter to obtain a white LED light source with low color temperature (< 6000K) and high color rendering (e.g., 90 or higher).

Example 1

As shown in fig. 1, when applied to a blue LED bulb light emitting device, the application of high color rendering index and low blue light healthy illumination is directly realized by forming a rare earth color light conversion material spray coating layer in an LED bulb light mask 102, and the preparation process steps are as follows:

(1) 1.9g of red luminescent organic rare earth material tris [5- (2, 2' -bipyridin-6-yl) -1,2, 4-1H-triazole ] europium (III) and 2.0g of tris [5- (1, 10-phenanthroline-2-yl) -1,2, 3-1H-triazole ] terbium (III) green luminescent organic rare earth material A1 (1) is prepared by mixing the composition of tris [ 3-fluoromethyl-5- (2, 2' -bipyridin-6-yl) -1,2, 4-1H-triazole ] europium (III) and tris [ 3-bromo-5- (2, 2' -bipyridin-6-yl) -1,2, 4-1H-triazole ] terbium (III) in a weight ratio of 2.2:1.5) in 150g of DMF to obtain a rare earth color light conversion material solution;

(2) 500g of polyurethane resin, 1.2g of defoamer (from922 Equal proportion of 150g of ethyl acetate and toluene, and stirring and dispersing uniformly to obtain the coatingA mother liquor of the material;

(3) Dropwise adding the rare earth color light conversion material solution prepared in the step (1) into the coating mother solution prepared in the step (2) under stirring, stirring and dispersing to uniformly disperse the rare earth color light conversion material solution, and filtering and defoaming to obtain the rare earth color light conversion coating;

(4) And (3) spraying the rare earth color light conversion coating obtained in the step (3) into the LED bulb lamp mask 102 to obtain a first light conversion luminescent film, wherein the film thickness of the first light conversion luminescent film is less than 50 mu m. The heat curing temperature is 110 ℃, and the curing time is 5min, so that the prepared first light conversion luminescent film can be combined with a blue light source to form white light under the excitation of the blue light LED light source.

Example 2

As shown in fig. 2, the application of the fluorescent lamp in the light-emitting device of a cold white T8/T5 type LED fluorescent lamp with a color temperature of 9100K (designed by a T8/T5 type fluorescent lamp based on a traditional inert gas filled mercury-containing fluorescent powder) is realized by adding a film-shaped color converter in a T8/T5 type LED fluorescent lamp mask 202, namely, the color converter is curled and molded, and the fluorescent lamp is attached to the inside of the mask to directly realize the healthy lighting application of high color rendering index and low blue light, and the preparation process steps are as follows:

(1) 2.5g of red luminescent organic rare earth material tris [5- (1, 10-phenanthroline-2-yl) -1,2, 4-1H-triazole ] europium (III) and 2g of yellow green luminescent organic rare earth material B1 (the composition of B1 is that tris [5- (4, 4' -dimethyl-2, 2' -bipyridyl-6-yl-1, 2, 4-1H-triazole ] europium (III) and the weight ratio of tris [ 3-fluoromethyl-5- (2, 2' -bipyridyl-6-yl) -1,2, 4-1H-triazole ] terbium (III) is 1.4:2.3 are mixed evenly, and then the mixture is added into a double screw extruder charging barrel after 1000g of Low Density Polyethylene (LDPE) base material particles and a certain auxiliary agent;

(2) Setting the extrusion temperature to 145-165 ℃, kneading, extruding, water-cooling, granulating, and drying to obtain the light conversion material functional master batch;

(3) And then blending the light conversion material functional master batch with the same polymer substrate particles according to a specific proportion, and adding the blend into a co-extrusion film blowing machine for film blowing and cutting to obtain a second light conversion luminescent film, wherein the thickness of the film layer is 0.8 mm. The light conversion material was contained in the second light conversion luminescent film in an amount of about 0.4%.

(4) The second light conversion luminescent film is reasonably cut according to the standard length of the lampshade of the T8/T5 type LED fluorescent lamp and the circumference of the lamp tube, and finally is combined with the inside of the T8/T5 type LED fluorescent lamp mask 202 in a physical fixing mode. At this time, on the basis of the white LED light source, the surplus blue light is absorbed and converted into red light and cyan light.

Example 3

As shown in fig. 3, the application of the color converter in the cold white LED tandem lamp light emitting device with the color temperature of 9101K directly realizes the healthy lighting application of high color rendering index and low blue light by remanufacturing the LED tandem lamp face mask 302 with the addition of rare earth color light conversion material, and the preparation process steps are as follows:

(1) Mixing 2g of red luminescent organic rare earth material tris [5- (1, 10-phenanthroline-2-yl) -1,2,3, 4-1H-tetrazole ] europium (III) and 1g of orange luminescent organic rare earth material A2 (the composition of A2 is tris [5- (1, 10-phenanthroline-2-yl) -1,2, 4-1H-triazole ] europium (III) and the weight ratio of tris [ 3-bromo-5- (2, 2' -bipyridyl-6-yl) -1,2, 4-1H-triazole ] terbium (III) is 4:3, and adding the mixture into a double screw extruder charging barrel after the mixture is uniformly mixed with 1000g of Low Density Polyethylene (LDPE) base material particles and a certain auxiliary agent;

(2) The extrusion temperature is 145-165 ℃, and the light conversion material functional master batch is obtained after the materials are kneaded, extruded, water-cooled, granulated and dried after melting;

(3) Blending the light conversion material functional master batch and the same polymer base material (LDPE) particles according to a standard proportion, and then adding the blend into a continuous blow pipe machine to carry out high Wen Zhu compression molding;

(4) The manufactured thick tube is reasonably cut according to the lengths of the LED row lamp bodies of different types, and the finally manufactured LED row lamp face mask 302 is combined with the lamp base part in a physical fixing mode. At this time, the LED tandem lamp mask 302 converts the surplus blue light into red light and orange light by absorbing it on the basis of the white LED light source.

Example 4

As shown in fig. 4, the application of the color converter in the cold white LED down lamp light-emitting device with a color temperature of 8200K can directly realize the healthy lighting application of high color rendering index and low blue light by replacing the light diffusion plate in the LED down lamp face mask 405 with a film-shaped color converter with rare earth color light conversion material, which basically comprises the following steps:

(1) 0.15g of red luminescent organic rare earth material tris [5- (4, 4 '-dimethyl-2, 2' -bipyridyl-6-yl-1, 2, 4-1H-triazole]Europium (III) and 0.15g red luminous organic rare earth material tris [ 3-fluoromethyl-5- (2, 2' -bipyridyl-6-yl) -1,2, 4-1H-triazole ]Europium (III) complexes, 100g of transparent Polycarbonate (PC) based on polycondensates of bisphenol A and phosgene2805, from Bayer Materials Science AG), 0.5g titanium dioxide rutile pigment (+>2233, from Kronos titanium) and an amount of methylene chloride are dissolved/dispersed after mixing;

(2) The obtained solution/dispersion was coated on the surface of a glass plate (wet film thickness 900 μm) using an applicator frame. After the solvent has been dried off, the film is separated from the surface of the glass plate and dried. Obtaining a circular photopolymer plate 404;

(3) The light-converting polymer plate 404 is reasonably cut according to the original size of the light diffusion plate of the white light LED down lamp, and finally is combined with the inside of the LED down lamp face mask 405 in a physically fixed manner. At the moment, on the basis of the white light LED down lamp light source, healthy illumination is realized by absorbing surplus blue light and converting the surplus blue light into red light.

Example 5

As shown in fig. 5, the application of the color converter in the light-emitting device of the cold white LED panel lamp with the color temperature of 7500K can be realized directly by replacing the light diffusion plate in the mask with a membranous color converter added with rare earth color light conversion material or adding a membranous color converter outside the mask. The preparation process comprises the following steps:

(1) 800g of polyurethane acrylic resin, 10g of resin UV curing agent and 40g of monofunctional acrylate diluent SR423 NS), 20g of a hexafunctional acrylate diluent (++>EM 265) stirring and dispersing uniformly, and adding 2.8g of red luminescent organic rare earth material tris [5- (2, 2' -bipyridyl-6-yl) -1,2, 4-1H-triazole]Europium (III) and 3.2g of tris [ 3-fluoromethyl-5- (2, 2' -bipyridin-6-yl) -1,2, 4-1H-triazole]Terbium (III) green luminescent organic rare earth material and 2.3g orange luminescent organic rare earth material A3 (A3 has the composition of tris [5- (2, 2' -bipyridyl-6-yl) -1,2,3, 4-1H-tetrazole)]Europium (III) and tris [5- (1, 10-phenanthroline-2-yl) -1,2,3, 4-1H-tetrazole]Terbium (III) and tris [5- (2, 2' -bipyridin-6-yl) -1,2,3, 4-1H-tetrazole]Mixing terbium (III) in a weight ratio of 4:2:1, stirring to uniformly disperse the light conversion material, and filtering and defoaming to obtain the rare earth color light conversion coating;

(2) Coating rare earth color light conversion coating on the surface of an LED panel lamp light guide plate 503 of PC or PMMA or PET polymer matrix by using a coating machine, wherein the thickness of the light guide plate is 500 mu m;

(3) Curing by irradiation with high pressure mercury lamp with energy of 1200mJ/cm ² Finally, a light conversion material film 502 with a thickness of 120 μm is formed on the surface of the light guide plate 503 of the LED panel lamp. At the moment, on the basis of the white light LED down lamp light source, healthy illumination is realized by absorbing surplus blue light and converting the surplus blue light into red light and orange light.

The Ra of the average Color Rendering Index (CRI), which is generally used to evaluate the color rendering capability of a light source, is obtained by averaging the values of the first eight special color rendering indices of CIE standard color samples (R1-R8), it is further necessary to increase the R9 index representing saturated red in addition to Ra to accurately represent red. Since the energy difference between the blue light of the higher energy level and the red light of the lower energy level in the color conversion process of the conventional blue light excited white light LED is converted into heat, the Luminous Efficiency (LER) of the warm white light LED is lower than that of the cool white light LED. On the other hand, cold white LEDs with high luminous efficiency often have an insufficient color rendering index, and there is a constraint relationship between the luminous efficiency and the color rendering index. The rare earth color light conversion material used in the invention can realize good compromise between the luminous efficiency and the color rendering index of the white light LED, and obtain the white light LED with high luminous efficiency and the average color rendering index close to 90 or higher.

Photophysical performance test of light emitting devices of examples 2 and 4: the cool white light LED of example 2 (denoted as LED 1) and the cool white light LED of example 4 (denoted as LED 2) were used as excitation light sources, respectively, to perform photometric detection of light emitted from the surface of the color converter, and integral measurement was performed using an ISP 500 integrating sphere spectrum analyzer and a CAS 140CT detector to detect all light emitted from the device. The measured spectra are used to obtain all relevant photometric data, such as CCT (correlated color temperature) values in kelvin [ K ], average color rendering index CRI values, and color rendering index (R9) values for reference color number 9 (red). The results are summarized in table 1 below.

TABLE 1 Performance of devices made from organic rare earth Complex light conversion materials in examples 2 and 4

Table 1 shows that the rare earth color conversion materials of example 2 and example 4 of the present invention can produce color converters that increase the average color rendering index CRI, R9 and reduce blue hazard. The rare earth color light conversion material improves the overall photophysical performance of a common cold white light LED lighting device, and shows the excellent characteristics of high color rendering index and low blue light of healthy lighting.

The above embodiments are only described to assist in understanding the technical solution of the present invention and its core idea, and it should be noted that it will be obvious to those skilled in the art that several improvements and modifications can be made to the present invention without departing from the principle of the present invention, and these improvements and modifications also fall within the protection scope of the claims of the present invention.

Claims

1. A light emitting device, characterized in that: comprising at least one LED and at least one color converter, said LED and color converter having a gap therebetween; the LED is a 15000-7000K cool white light LED or an LED with a central emission wavelength of 380-480 nm; the color converter comprises a rare earth color light conversion material and a polymer matrix material, wherein the rare earth color light conversion material is combined or blended with the surface of the polymer matrix material, and the rare earth color light conversion material is obtained by compounding a red luminescent organic rare earth material and a green luminescent organic rare earth material;

The red luminescent organic rare earth material is selected from at least one of tris [5- (2, 2' -bipyridin-6-yl) -1,2, 4-1H-triazole ] europium (III), tris [5- (1, 10-phenanthroline-2-yl) -1,2, 4-1H-triazole ] europium (III), tris [5- (4, 4' -dimethyl-2, 2' -bipyridin-6-yl-1, 2, 4-1H-triazole ] europium (III), tris [ 3-fluoromethyl-5- (2, 2' -bipyridin-6-yl) -1,2, 4-1H-triazole ] europium (III), tris [5- (2, 2' -bipyridin-6-yl) -1,2,3, 4-1H-tetrazole ] europium (III) and tris [5- (1, 10-phenanthroline-2-yl) -1,2,3, 4-1H-tetrazole ] europium (III);

the green luminescent organic rare earth material is selected from at least one of tris [5- (2, 2' -bipyridyl-6-yl) -1,2, 4-1H-triazole ] terbium (III), tris [ 3-phenyl-5- (2, 2' -bipyridyl-6-yl) -1,2, 4-1H-triazole ] terbium (III), tris [5- (1, 10-phenanthroline-2-yl) -1,2,3, 4-1H-tetrazole ] terbium (III), tris [ 3-bromo-5- (2, 2' -bipyridyl-6-yl) -1,2, 4-1H-triazole ] terbium (III), tris [5- (2, 2' -bipyridyl-6-yl) -1,2,3, 4-H-tetrazole ] terbium (III), and tris [ 3-fluoromethyl-5- (2, 2' -bipyridyl) -1,2, 4-H-tetrazole ] terbium (III);

the rare earth color light conversion material is combined with a polymer matrix, and the addition amount of the rare earth color light conversion material in the polymer matrix depends on the correlated color temperature to be achieved;

The red luminescent organic rare earth material and the green luminescent organic rare earth material are proportioned according to the following weight proportion ranges to obtain a yellow luminescent organic rare earth material, wherein the proportion range is 1:1-10; the red luminescent organic rare earth material and the green luminescent organic rare earth material are proportioned according to the following weight proportion ranges to obtain the red orange luminescent organic rare earth material, wherein the proportion range is 1:0.1-1; the red luminescent organic rare earth material and the green luminescent organic rare earth material are proportioned according to the following weight proportion ranges to obtain an orange luminescent organic rare earth material, wherein the proportion range is 1:0.1-4; the red luminescent organic rare earth material and the green luminescent organic rare earth material are proportioned according to the following weight proportion ranges to obtain a yellow-green luminescent organic rare earth material, wherein the proportion range is 1:2-10.

2. A light-emitting device according to claim 1, wherein: the color converter further comprises at least one barrier layer to oxygen and/or water.

3. The light-emitting device according to claim 1, further comprising an auxiliary agent, wherein the auxiliary agent is at least one of a flame retardant, an antioxidant, a light stabilizer, an ultraviolet absorber, a blue light absorber, a radical scavenger, and an antistatic agent.

4. The light-emitting device according to claim 1, wherein the rare earth color conversion material is combined with the polymer matrix material by at least one of casting, granulating and tabletting, granulating and film-blowing, coating and film-scraping, and printing.